Catalytic domain of the dual-specificity Protein Kinase, MAP kinase kinase 7. Protein kinases (PKs), MAP kinase kinase 7 (MKK7) subfamily, catalytic (c) domain. PKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine or tyrosine residues on protein substrates. The MKK7 subfamily is part of a larger superfamily that includes the catalytic domains of other protein serine/threonine kinases, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. The mitogen-activated protein (MAP) kinase signaling pathways are important mediators of cellular responses to extracellular signals. The pathways involve a triple kinase core cascade comprising the MAP kinase (MAPK), which is phosphorylated and activated by a MAPK kinase (MAPKK or MKK), which itself is phosphorylated and activated by a MAPK kinase kinase (MAPKKK or MKKK). MKK7 is a dual-specificity PK that phosphorylates and activates its downstream target, c-Jun N-terminal kinase (JNK), on specific threonine and tyrosine residues. Although MKK7 is capable of dual phosphorylation, it prefers to phosphorylate the threonine residue of JNK. Thus, optimal activation of JNK requires both MKK4 (not included in this subfamily) and MKK7. MKK7 is primarily activated by cytokines. MKK7 is essential for liver formation during embryogenesis. It plays roles in G2/M cell cycle arrest and cell growth. In addition, it is involved in the control of programmed cell death, which is crucial in oncogenesis, cancer chemoresistance, and antagonism to TNFalpha-induced killing, through its inhibition by Gadd45beta and the subsequent suppression of the JNK cascade.